ProDave

If the house really is "super air tight" it will need mvhr to meet building regs. Perhaps you have the wrong make of recirculating cooker hood I don't find ours any noisier than a venting one (some of those can sound like a jet engine at full speed) and ours exhausts the air at the sides and we don't notice it.

What is your issue with an ASHP? Heating just low temperature UFH it will use less than one third the amount of electricity than a heat battery will. So your off peak rate would have to be less than 1/3 the peak rate to make it cheaper. If the rest of your house is oil, why do you want off peak? a penalty of off peak is the day rate is higher, so you have to use a lot of off peak to make it worthwhile. The cost of buying an ASHP must be very similar to the cost of a heat battery so would seem a better and simpler choice to me.

How can there be no cover if it's under a driveway? how do you know it is still in use? It sounds more like something disused that was filled in to enable the driveway over it if no lid?

Yes that's it, turn off the electric undo that nut and remove the plastic cover then post a picture of the inside and someone will tell you which is the thermostat. No water will escape doing that.

Does anyone admit to actually eating a Fray Bentos pie? Once as an experiment can be accepted but to eat a second?

This is the immersion heater. Follow the white cable, it should go to a switch on the wall. Turn that switch off. Then remove the screw that is visible in the picture, that holds the plastic cover on. Post a close up picture of the inside and we will tell you what to adjust. No it won't leak water. Turn the switch back on when done or the immersion heater won't work.

Assuming your front door has level access, then you just need normal steps, no ramp etc.

Our BCO just looked at the marks on the panes in the corner stating what was toughened and what was laminated. They only did this for "low level" windows and glazed doors. Unless you have some dodgy non compliant glass (unlikely) that is all that needs to be done. But if you can fit a bit of 4 by 2 in a way you can remove it later without leaving much to touch up, that might be the solution. But I fear that on it's own will not be enough, you will need spindles at <100mm spacing as well.

I got around to watching it today. Well it was a lot better than I expected. Nothing I did not know, but it did seem a fairly clear explanation of what solar panels do and heat pumps as well About the only thing that stood out for me is the typical MCS costs with a payback time of 10 years or more. I was quite impresses by the Octopus development centre and their test houses and training system.

The point of an inlet in bedrooms and living rooms and gaps under the doors, is fresh air circulates all around the house. Your proposal would leave stale air in the bedrooms not circulating anywhere and not getting refreshed.

MVHR is the way to go. Normally it is extract from all "wet" rooms, so kitchen, utility, bathrooms, and fresh air in to bedrooms and living rooms.

Crack on and do it. Keep a copy of that letter in case someone complains.

I would use my quite old digital camera that does not know about such things, rather than a phone camera.

The reason I say patch up the old one, it is will be easier to prove it has been there and in use for a long time. A new one arriving on a low loader and the old one taken away, would be easy for someone to say it's use is new. Post some pictures of how bad the old one is (without anything in the photo to give away the location)

To export and get paid for it, requires an MCS install. Why do you WANT to export? A PV system with batteries should be all for self use imho with export set to 0. That is perfectly legal for an electrician to wire up and as long as you have notified the DNO. The DNO rules seem prehistoric that they only look at the inverter power and assume that is what you WILL export and that is what they give permission for (or not) Try a G99 application for what you want and see what they say. Report back if they talk about charging you network upgrade costs, they should not be doing that any more but have yet to hear how people get on under the new rules.

Yes tread carefully. They will argue the existing one is derelict and likely refuse. That's why I say do whatever it takes to get the existing one habitable and move in, then get a certificate of lawful development. That certificate basically acknowledges that the existing use has been ongoing for so long that the council cannot enforce any change. Applying for that certificate once the caravan is habitable and occupied, should be your first contact with the council. Only when you have that, should you start discussing a permanent dwelling or replacing it with a new caravan. You can self build a caravan compliant well insulated building as pointed out already done on Grand Designs. To be a "caravan" it has to be within certain size limits which is just a little over 100 square metres if you go to the maximum size, and single storey. And it must be moveable. But it does not need to be on wheels, built in sections which can be separated and then lifted by a crane onto a low loader is sufficient to comply. You can get lots more advice on the details if that is how you proceed. But keep quiet and get that existing van patched up and occupied.

Yes, the belief that "modular homes" will solve the housing crisis. Just as the people that talk about converted containers etc. The reality is the bottleneck is land and planning permission. Only then can you build a house and only then can you decide conventional build or modular. Modular is unlikely to be cheaper, but has some advantages like quicker on site time and better precision.

Planning is the crux here. Others may know the local policies in this area. But I would quietly patch up the existing static caravan so it is habitable, if not very pretty or desirable, and make it look lived in, even move in for a period over the summer? then apply for a certificate of lawful development. That gives you a fallback to rebuild anything that complies with the legal definition of a "caravan" which can in fact be a very well insulated bungalow of about 100 square metres. With that secured as a fallback you can then investigate planning for something different.

I read that link, was dismayed, and even got as far as trying to respond but was even more dismayed. This is all about more red tape, more rules, more paperwork for installers etc. This will do NOTHING to speed up the rate of heat pump installs. Typical government mentality, regulate everything, even though we have a PM who says he is in favour of the opposite. I gave up the will after the first few questions trying to respond, it is only looking for answers to approve their plans or make minor alterations to them. What I wanted to say is the whole plan is a crock of steaming excrement, it just burdens the market with yet more paperwork and expenses and ensures is is just the big companies who are set up to milk the system and collect the grant money that will operate in this type of market. What is needed is less and simpler regulation and to encourage the small plumbing end electrical businesses, even sole traders, to be involved in heat pump installation. That is the only way you will get the thousands of electricians and plumbers we already have on board and installing heat pumps.

Started at 7PM, I am recording it to watch later, watch it on 5+1 or catchup. It will be interesting to see if it's a well reasoned assesment of their usefulness or not. Also explores if heat pumps are worth it.

I had to do a job at the local Chinese takeaway. It appeared at least half the baffles are missing from the hoods with the innards of the hood and extract pipe clearly visible, so I bet they get a lot more fat up their chimney? I can well believe the massive heat loss / waste, there was quite a long line of cookers all with the hoods and extraction above them.

Yes it does seem to be an industrial scale mvhr recovering heat from the kitchen ventilation system. I guess the biggest challenge and why this is "new" with it's new design of heat exchanger, is the high grease content of the exhaust air it is recovering heat from. One can imagine a condensate drain that is collecting cooking fat?

Did the people specifying the size of the ASHP have ALL the details of the build, individual wall U values etc? Jeremy's spreadsheet proved very accurate and real as built heat loss closely follows what that predicted in my case, far more accurate than anything else including the SAP calculations. My only comment is who specified an UFH system with a flow temperature of 50 degrees? You should be running at a lot lower than that. It is a big house but if the calculations are saying 8627W for delta t 30 that is pretty good for such a large house. and it won't often be -10 in the SE and not for long (unlike here when -10 for a week is common in winter)

You need a good lawn. My neighbour has one and his "lawn" is not flat enough and has too many humps and dips and it frequently gets stuck. He also has to prepare the lawn at the start of the season with the ride on mower. The robot would not cope with the long wet winter growth.

So why can't the DNO say go ahead export as much as you like, but your inverter may trip on over voltage. That is after all what that function is there for. It would allow people like me who have no intention to export anything to fit more PV for self use, and if things go wrong and too much accidentally tries to export the inverter voltage limit would stop it overloading the network.